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1.
ACS Omega ; 9(14): 16743-16758, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38617631

RESUMO

This study presents an in-depth investigation into the wear characteristics of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with microsized MoS2 and nanosized graphite particles. The objective is to enhance the wear resistance of the UHMWPE by examining the effects of various parameters and optimizing the wear performance. To achieve this goal, wet wear tests were conducted under controlled conditions, and the results were compared between composites with micro MoS2 and nano graphite reinforcements. The Taguchi method was employed to design the experiments (DOE) using an L9 orthogonal array. Four key parameters, namely, reinforcement percentage, load, speed, and track radius, were varied systematically to analyze their impact on wear characteristics, including wear rate, frictional forces, and the coefficient of friction (COF). The data obtained from the experiments were subjected to analysis of variance (ANOVA) to identify the significant factors affecting wear behavior. Subsequently, the optimal wear parameters were determined through regression analysis, allowing for the prediction of wear characteristics under the optimum conditions. This research not only provides insights into the comparative performance of micro MoS2 and nano graphite reinforcements in UHMWPE composites but also offers a comprehensive approach to optimizing wear resistance by employing advanced statistical and experimental techniques. The findings contribute to the development of more durable and wear-resistant materials with potential applications in various industries, such as those investigated in the study, which are commonly employed, such as automotive, aerospace, medical devices, or manufacturing.

2.
ACS Omega ; 9(5): 5230-5245, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38343954

RESUMO

Magnesium, which is lightweight and abundant by nature, was widely used in the 19th century to make parts for automobiles and airplanes. Due to their superior strength-to-weight ratios, magnesium alloys were favored for engineering applications over unadulterated magnesium. These alloys result from the combination of magnesium with various metals, including aluminum (Al), titanium (Ti), zinc (Zn), manganese (Mn), calcium (Ca), lithium (Li), and zirconium (Zr). In this study, an alloy of magnesium was created using the powder metallurgy (PM) technique, and its optimal performance was determined through the Taguchi-Gray (TG) analysis method. To enhance the alloy's mechanical properties, diverse weight fractions of silicon carbide (SiC) were introduced. The study primarily focused on the Mg-Zn-Cu-Mn alloy, achieving the optimal composition of Mg-3Zn-1Cu-0.7Mn (ZC-31). Subsequently, composites of ZC-31/SiC were produced via PM and the hot extrusion (HE) process, followed by the assessment of the mechanical properties under various strain rates. The use of silicon carbide (SiC) resulted in enhanced composite densities as a consequence of the increased density exhibited by SiC particles. In addition, the high-energy postsintering approach resulted in a decrease in porosity levels. By integrating silicon carbide (SiC) to boost the microhardness, as well as the ultimate compressive and tensile strength of the composite material, we can observe significant improvements in these mechanical properties. The experimental findings also demonstrated that an augmentation in the weight fraction of SiC and the strain rate led to enhanced ductility and a shift toward a more transcrystalline fracture behavior inside the composite material.

3.
ACS Omega ; 9(7): 7634-7642, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38405511

RESUMO

Present investigation includes the magnetizing roasting of low-grade iron ore fines followed by grinding and beneficiation using magnetic separation. The hematite iron ore used in the investigation contains 53.17% T Fe, 10.7% SiO2, and 4.5% Al2O3. Powdered bituminous coal of 210 µm size with an ash content of 12.5% and fixed carbon of 54.25% was used as reductant during magnetizing roasting. Optical microstructures have shown where iron and silicate minerals are found and how they are interconnected. Hematite is the most abundant material in the specimen and is found in fine- and medium-sized grains. Hematite emerged as the predominant iron-bearing mineral, accompanied by magnetite and goethite phases in smaller proportions according to XRD analyses. The primary gangue mineral identified by scanning electron microscopy is quartz, with gibbsite, feldspar, and pyrolusite present in lesser levels. The effects of iron/coal ratio, roasting time, and roasting temperature were considered as variable parameters. Hematite ore's magnetic characteristics were significantly impacted by magnetizing roasting. By selectively magnetizing roasting, hematite is transformed into magnetite. With an Fe grade of 65.25% at a recovery value of 72.5% in the concentrate, magnetic separation produced the greatest result for Fe. The performance of magnetization and therefore the magnetic separation process were shown to be significantly impacted by temperature, reductant %, and roasting duration in this investigation.

4.
ACS Omega ; 8(37): 33543-33553, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37744866

RESUMO

The study presently conducted focused on analyzing a solar-powered desalination setup that had a double slope. It can recycle blackish water into drinking water with solar energy. Not only does this result in a significant decrease in carbon emissions but it also represents an environmentally beneficial alternative that is particularly suited for arid locations that are lacking of electrical infrastructure. This system was equipped with a PVT system which makes the system self-sustainable and a CPC collector and implemented the use of aluminum oxide (Al2O3) nanoparticles to enhance its energy efficiency. Energy matrices, economic analysis, and life cycle conversion efficiency were evaluated. The study was conducted annually in New Delhi, with input data provided by IMD in Pune, India. MATLAB was used for the analytical calculations. Energy and exergy were utilized to determine the average annual energy output, which was found to be 8.5%. Additionally, the average energy payback time was calculated to be 16.16%, the average energy payback factor was 13.91%, and the average life cycle cost conversion efficiency was 7.15% higher. The proposed system demonstrated superior performance compared to the previous system in terms of annual yield, energy payback time (EPBT), efficiency of life cycle cost (LCCE), and factor of energy payback (EPBF). The hybrid system has the potential to meet the future demand for potable water and become self-sustainable.

5.
ACS Omega ; 8(34): 31002-31008, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37663468

RESUMO

Conventional greases have an exceptional place in the field of lubrication. They are unique in the sense of their areas of application and are very difficult to replace with other lubricating substances for the same reason. The advancements in the field of nanoparticles and the results they provide as an additive in greases have great scientific interest as they improve the tribological properties of greases to a great extent. The current work's aim is to synthesize a nanogripe using graphene oxide (GO) nanoparticles to lithium grease (Li grease), which will increase the tribological properties of the plain Li grease. Steps were taken to investigate the impact of variation of load on the frictional and wear characteristics of nanogrease. Synthesis of nanogrease and tribological evaluation were performed with a magnetic stirrer with a hot plate and a four-ball tester. Results indicated that nanogrease exhibits better tribological properties. It is also found that the antiwear and frictional properties of grease are not proportional to the wt % of GO nanoparticles. It is also detected that with the increase in load, the tribological properties of nanogrease increase.

6.
ACS Omega ; 8(30): 26828-26836, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37546647

RESUMO

In the current study, a two-stage stir cast process was used to produce Al6082 reinforced with sized graphite particulates, and the material's mechanical and tribological properties were analyzed. The graphite content in the Al6082 alloy was increased from 2 to 6% in steps of 2 wt %. The impact of graphite addition to Al6082 was evaluated using microstructural micrographs, hardness test, tensile test, and wear test outcomes. The matrix alloy's microstructure and particle distribution were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. The microstructure of Al6082 shows that the reinforcement particles are evenly distributed throughout the matrix. Although the hardness of metal-matrix composites was slightly reduced when graphite was added at concentrations of up to 6 wt %, the material's tensile strength and wear resistance were significantly improved. Micrographs taken by a microscope were used to examine the fractured surfaces of tensile test specimens. Wear experiments were performed using a conventional pin-on-disc tribometer to examine the tribological properties of both unreinforced matrix and graphite composites. With the addition of 2, 4, and 6 wt % of graphite particles, the composites' wear resistance was significantly improved. Wear of alloys and their composites was analyzed to determine how load and sliding speed impacted wear loss.

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